GAH...she's not working. Today's lesson.

[sablesurfer]

Brew lesson today! Electric brew system with recirculating mash. I was trying pretty big grain bill for this little pot, but the sieve in the bottom has handled well over 5lbs more in the big pot. I followed the directions for a 1.33 ratio mash in. Put grains in, stirred and stirred and stirred. Wasn't enough so I added a bit more water, stirred and stirred and stirred. Now I start to notice cavitation in my pump, so I add a bit more water. Should have been enough.
Then more cavitation and odd sounds, I open and close the valve nothing changes. Deciding I have heard too many stories about burnt out elements I shut everything down and to have a look. Pull the bag out and drop in another pot. Then try to get the sieve (mounted on bolt/legs) out of the pot. It has been crushed. Pushed down so much it has actually reversed past the narrower diameter of the pot. It doesn't come out without a LOT of force.
I can only think that this was a case of too little water, too much pump, and suction of the grain bag sealing against sides of pot. Once I rebuilt the sieve and added another half gallon of water (3 gal brew) then everything started recirculating as normal. Sigh. Thought I'd share.

 

[sablesurfer]

Yeah, not sure there is much structural integrity here anymore.

 

[wilserbrewer]

I have seen this happen before...perhaps it would be good practice to have a vertical piece of copper tubing alongside the bag drilled with holes...kind of a relief passage to provide flow. Or for that matter, perhaps placing a brew spoon outside the bag and vertically in the kettle would provide enough "daylight" for the wort to avoid "pump lock"

 

[sablesurfer]

Or kill the system during mash in. This brew taught me why I want a quick switch to disable the element and one for the pump. Right now I have to turn system off or unplug the lead to the element. A switch would work better.

I have to kill the element when I stop the pump, because my sensor is up on my wort return and when it gets exposed to ambient temps when the pump stops.

Lessons lessons....lol.

 

[Epimetheus]

Maybe get a sheet of pierced aluminum from the hardware store and cut it to fit the bottom, it is the stuff they use for radiator covers.